1. Field of the Invention
The present invention relates to an access unit which is capable of accessing a record medium including a user area so that a user can record data, and an access method, an access program and a control unit for the same purpose.
2. Description of the Related Art
In recent years, the density of a record medium has been heightened and its capacity has become larger. Hence, it has been increasingly important to make a record medium reliable. In order to secure the reliability of a record medium, there is a method in which an alternate sector with a defective sector is provided so that no access can be gained to the defective sector (e.g. refer to Patent Document 1). Besides, for the purpose of obtaining a record medium's reliability, a test processing for determining an optimum access parameter is executed in a recording-and-regenerating unit. Thereby, the access parameter is adjusted for the record medium.
The access parameter is, for example, the power of recording. The recording power is the power of a laser which irradiates the record medium when data is recorded. In the test processing for determining the optimum recording power the recording power at which the record medium is irradiated is adjusted.
The access parameter is adjusted based on the result of a test record and a test regeneration for a read-in area or a read-out area. The read-in area is allocated to an inner circumference of the record medium. The read-out area is allocated to an outer circumference of the record medium.
However, if the necessity of a test processing arises while data is recorded or regenerated by the access of an optical head to a user area, the test processing will take a longer time. This is because in the test processing, the optical head has to seek a read-in area or a read-out area, so that a test record and a test regeneration can be made for the read-in area or the read-out area.
If the test-processing time becomes longer, disadvantages may be raised, such as a disturbance in the regeneration of AV data, a break in the recording of a picture, and lengthening the time to execute the recording of user data.
In addition, if the density of a record medium becomes higher, this requires that data be recorded and regenerated using an access parameter which is most suitable for a change in recording-and-regeneration conditions. Hence, a test processing needs frequently executing according to a change in recording-and-regeneration conditions. As a result, the above described disadvantages become increasingly conspicuous.
Patent Document 1: Japanese Patent Laid-Open No. 7-182792 specification